The present invention relates to the field of magneto-electric transducer devices for sensing movement. These devices use a magnetic circuit having an air-gap in the neighborhood of which may move a ferromagnetic bar propelled with the movement to be revealed. An electric circuit in the form of a coil is wound around the magnetic circuit and, during the movement of the bar, it is the seat of an electric voltage tied to any variation of a magnetic flux which might be created therein.
This flux may come from a source of magnetism such as a magnetized bar, either inserted in the fixed circuit, or formed, after magnetization, by the mobile ferro-magnetic bar itself. The electric voltages or currents thus created are finally used in suitable measuring devices.
Such sensors are widely used in practice, and their construction is now well-known, adapted to the different conditions of use normally met with in practice.
It is a different matter when the environmental conditions are more severe, particularly those which concern the temperatures. Thus, picking up the movement of mobile elements in an aircraft reactor requires satisfactory operation at temperatures of more than 400.degree. C. The use of conventional coils, of the multi-turn type is then to be discarded, as well as connections electrically insulated by organic sheaths, and the presence and/or the length of connections is even to be strictly limited, for example by forming one of them by means of the "ground" return, if the support of the device is electrically conducting.